Clamp connector



Sept. 12, 1967 H. R. WENGEN CLAMP CONNECTOR Filed May 25, 1964 iNVENTUR HEN/9V wan/Gard United States Patent 3,341,804 CLAMP CONNECTOR Henry R. Wengen, Poughkeepsie, N.Y., assignor to Fargo Mfg. Company, Inc., Poughkeepsie, N.Y., a corporation of New York Filed May 25, 1964, Ser. No. 369,837 1 Claim. (Cl. 339-98) This invention relates generally to clamp connectors and more particularly to a connector designed to electrically and mechanically clamp an insulated cable to a grounding wire.

There is presently in use today a type of electrical cable providing adjacent, substantially parallel messenger and multi-strand conducting cables which are insulated from one another but together with the same material presenting a FIGURE 8 cross section. When it becomes necessary for the messenger to be electrically grounded it has been a problem with presently available clamps in view of the necessity of skinning back the messenger insulation accurately and to the limited extent required without damaging the multi-strand conductor or insulation immediately surrounding the multi-strand conductor.

The invention herein disclosed has as its principal object the provision of a clamp which is an improvement of clamps of the type shown in United States Patents Nos. 2,456,808, 2,469,542, and 2,858,522 with which a messenger cable can be electrically and mechanically connected to a ground cable without the necessity of skinning back any part of the insulation surrounding the messenger cable.

It is a further object of this invention to provide an irnproved clamp connector which can hold firmly a messenger cable and ground wire and which can be conveniently and easily used.

It is still a further object of this invention to provide a clamp connector with which a firm clamping action can be achieved about an insulated messenger cable preventing loosening of the joint due to cold flow of the insulating material itself.

These and other objects of the invention are accomplished by the provision of a clamp connector with a spacer bar in which parallel horizontal rows of teeth of predetermined spacing are formed on spacer bar and clamp jaws as described herein with references to the drawings, in which:

FIG. 1 is a plan view of a clamp connector constructed in accordance with the teachings of this invention with the multi-strand cable, messenger cable, and ground wire shown in phantom;

FIG. 2 is a sectional view taken along the line 2-2 in the direction of the arrOWs as indicated in FIG. 1;

FIG. 3 is a sectional view taken along the line 3-3 in the direction of the arrows as indicated in FIG. 2; and

FIG. 4 is a sectional view taken along the line 4-4 in the direction of the arrows as indicated in FIG. 2.

The base or body of the connector is indicated in the figures by the numeral and upstanding arm portions integral therewith are indicated by the numerals 11 and 12 providing a U-shaped cross section with flanges 13 and 14 extending outwardly respectively adjacent the free edges of arms 11 and 12. Clamping jaw 15 is integral with body 10 and transverse thereof with its inwardly directed face indicated by the numeral 16.

A slide member 17 rides longitudinally within the space defined between arms 11 and 12 and supports transverse movable jaw 18 integrally therewith with face 19 thereof directed toward face 16 of stationary jaw 15. Slide member 17 is provided with screw threaded bore 20 extending axially of its length. Engaging these threads are the threads of bolt shank 21. Head 22 of bolt shank 21 lies 3,341,804 Patented Sept. 12, 1967 outside of body 10 abutting surface 23 thereof. In this manner, thrust may be exerted by the bolt thread as the shank 21 is turned with respect to the remaining parts of the assembly by rotation of head 22 which continually abuts surface 23. In this manner jaws 15 and 18 can be drawn toward one another or separated from one another.

Spacer bar 24 is provided between jaws 15 and 18 extending parallel thereto with surface 25 of the spacer bar facing surface 16 of jaw 15 and surface 26 of the spacer bar facing surface 19 of jaw 18. The length of spacer bar 24 is such that it extends beyond the outer edges of flanges 13 and 14. At those points it is provided with arms 27 spaced a distance greater than the distance between the flange edges and which arms are inturned as at 28 to provide parts underlying those flanges or rails. Accordingly, with the bar in position it may not be accidentally separated from body 10 either by direct lateral movement or past jaw 15 or jaw 18 and will be free to shift toward either of these jaws.

T-he spacer bar 24 is provided with two parallel horizontal rows of teeth extending from each surface 25 and 26. There are three teeth in each row as shown in the figures. Each of the teeth in the upper row extending from surface 25 is indicated by the numeral 25 while each of the teeth in the lower row is indicated by the numeral 25". Likewise, each of the teeth in the upper row extending from surface 26 is indicated by the numeral 26' While each of the teeth in the lower row extending from surface 26 is indicated by the numeral 26". Each of the teeth is triangular in cross section in the vertical plane perpendicular to its respective face and rectangular in cross section in the horizontal plane perpendicular to its respective face.

Surface 16 of jaw 15 is provided with two parallel, horizontal rows of teeth, each row having two teeth with each tooth of the upper row indicated by the numeral 16 and each tooth of the lower row indicated by the numeral 16". The teeth in each row on surface 16 are spaced so that the respective center tooth in the row on surface 25 will lie between them with the remaining two teeth of the row on surface 25 disposed one on each side of the pair projecting from surface 16.

Surface 19 of jaw 18 is also provided with two parallel horizontal rows of teeth, each row having two teeth with each tooth of the upper row indicated by the numeral 19' and each tooth of the lower row indicated by the numeral 19". The teeth in each row on surface 19 are spaced so that the respective center tooth in the row on surface 26 Will lie "between them with the remaining tWo teeth of the row on surface 26 disposed one on each side of the pair projecting from surface 19.

The point of each tooth indicated in the figures by the numerals 25a, 25"a, 26a, 26"a, 16'a, 16"a, 19'a, or 19"a, defines a horizontal line with the points 25a and 16'a lying in substantially the same plane as do the points 25"a and 16"a. Also, points 26'a and 19a lie in the same horizontal plane as do points 26"a and 19"a.

The distance between points 16'a and 16"a is the same as the distance between the points 19'a and 19"a. Likewise, the distance between points 25'a and 25"a is equal to the distance between points 26'a and 26"a. In other words, points 16'a, 25a, 26a and 19a lie in substantially the same plane and the points 16"a, 25"a, 26"a and 19"a lie substantially in the same plane which is horizontal and parallel to the plane of the upper points.

The distance between upper and lower points is greater than the diameter of ground cable 29 but less than the diameter of messenger cable 30 so that the teeth will allow firm sitting and gripping of the ground cable while piercing the insulation 30' of the messenger cable when bolt 22 is manipulated drawing jaw 18 toward jaw 15 with ground cable 29 between teeth 16', 16", 25' and 25" and messenger cable 39 between the facing teeth projecting from surfaces 26 and 19. The multi-strand cable 31 is joined to messenger 30 by insulation 30' which maintains the messenger and multi-strand cable together in a cable commonly used today. The messenger and multistrand conducting cables lie substantially parallel and adjacent and are joined by the insulation 30' to provide the configuration shown in FIG. 2 and this dual cable is supplied to the trade in this configuration.

It is noted that the clamp is easily used and quite versatile in that the position of messenger cable can be interchanged with the position of ground cable if desired or inadvertently while accomplishing the same result in view of the fact that the teeth of the upper row are spaced from the teeth of the lower row a distance greater than the diameter of the ground cable but less than the diameter of the messenger.

When it is necessary for the messenger cable 30 to be electrically grounded there is no necessity for skinning back a portion of the insulation 30. The teeth in the unit pierce the insulation of the messenger on the one side of the spacer while the teeth on the other side of the spacer perform the function of holding the grounding cable firmly. Since the teeth are on both jaws and both sides of the spacer, the cable for ground and the messenger cable can be interchanged in position.

Since piercing teeth are provided on all jaws they penetrate the insulation on both sides of the conductor thereby providing an even distribution avoiding cold flow of the insulating material itself. In other words, if the jaws were to be provided with teeth on one side only so as to only bite or pierce on one side of the insulating material of the messenger cable, the other side would tend to flatten out the insulation which, in turn, would gradually ease out between the conductor and the jaw or flow which ultimately would mean the loosening of the joint. It is seen, therefore, that the insulation is well taken care of by the teeth while a good electrical engagement is accomplished. Likewise, only metallic pressure points are maintained.

Thus, among others, the several objects of the invention, as specifically aforenoted, are achieved. Obviously, numerous changes in construction and rearrangement of parts might be resorted to without departing from the spirit of the invention as defined by the claim.

I claim:

In a connector for establishing electrical contact between an insulation covered cable and a ground cable without destroying the insulation, said connector being of the type having a channel-shaped body, a stationary jaw formed at one end of said body, a sliding jaw movable in said channel toward and away from said stationary jaw, a spacer bar slidable within said body between said jaws, a stationary jaw face of said stationary jaw facing said spacer bar, a movable jaw face of said sliding jaw facing said spacer bar, a first jaw face of said spacer bar facing said movable jaw face, a second jaw face of said spacer bar facing said stationary jaw face, said spacer bar being disposed between said cables in the operative position of said connector, that improvement consisting of providing first insulation piercing teeth on said first and second jaw faces, said first insulation piercing teeth and said spacer bar being formed of an electrically conductive material whereby in the operative position of said connector electrical contact between said cables is established by said spacer bar and said first insulation piercing teeth, and providing second insulation piercing teeth on said stationary and said sliding jaw faces, each of said teeth having a triangular cross section configuration in the vertical plane with the apex of the triangle defining a line in the horizontal plane, and the teeth of each of said jaw faces arranged in parallel upper and lower horizontal rows with the apex of facing teeth of each of said upper rows in the same horizontal plane and facing teeth of each of said lower rows in the same horizontal plane whereby upon movement of said sliding jaw toward said stationary jaw said teeth positively pierce insulation of an insulation covered cable encountered thereby in the absence of a wiping action so that in the operative position of said connector said first and second insulation piercing teeth mechanically support said cable.

References Cited UNITED STATES PATENTS 964,376 7/1910 Blackburn 248-226 2,469,542 5/1949 Becker 248l 3,248,684 4/1966 Hubbard et a1 339 FOREIGN PATENTS 67,298 2/ 1951 Netherlands.

MARVIN A. CHAMPION, Primary Examiner.

EDWARD C. ALLEN, PATRICK A. CLIFFORD,

Examiners. J. H. MCGLYNN, Assistant Examiner. 

